Electronic cigarette is also termed as e-cig, personal vapor, Electronic Nicotine Delivery System (ENDS). Smoking a e-cigarette is now termed as vaping, as now modern e-cigarette produce vapour form the liquid in its tank. There are many types of e-cigarette and wikipedia has even categorised them as by generations from first to third.
First generation e-cigarettes are termed as ‘cigalikes’ as they look like a normal cigarette in shape, they have a LED light that signals user it is working/activated as they inhale from mouth piece. These e-cigarette consist of battery component and e-liquid (e-juice) Component. Few models have rechargeable batteries.
Second generation are termed as Personal vapor (PV), these are much famous and used widely. PV consist of two parts one is the battery part and another is the e-liquid tank (Clearomizer), they can be refilled without changing the tank. Batteries are rechargeable with USB charger, and are available in various power capacity like 950 mAH, 900 mAH, 1100 mAH and so on. Maximum of all batteries have a switch to power On and Off, same button is used to heat up the coil inside atomizer which is placed with the silica fiber soaked with e-juice which make the vapour.